This invention relates generally to a mobile surface scrubber for scrubbing a surface wetted with cleaning solution, and more particularly the invention relates to a solution recovery system for recovering cleaning solution from the wetted surface.
Mobile surface scrubbers typically include a cleaning solution dispensing system, scrub brushes for scrubbing the wetted surface and one or more squeegees for removing used cleaning solution from the surface. The squeegees are frequently connected to a vacuum to improve the removal of the cleaning solution. In addition, scrubbers frequently include sweeper brushes to sweep debris from the surfaces, either concurrently with or independently from the surface scrubbing operation. The sweeper brushes are usually adapted to sweep the debris into a recovery bin. A vacuum is also frequently used to draw debris into the recovery bin.
The scrubbers may be driven over a surface such as the floor of a factory or warehouse so that the sweeper brushes sweep debris into the bin and the scrubber brushes scrub the wetted floor. Although machines of this type work well when traveling forward in a straight line, cleaning solution may bypass the squeegees, leaving a trail of solution behind the machine, when the machine turns left or right.
Several developments have been made to improve the performance of the squeegees during turns so that less cleaning solution bypasses the squeegees. For instance, the rear squeegee blade has been formed in an arc or chevron so that the cleaning solution is directed away from the ends of the blade and toward its center where a vacuum is located. Further, some machines have been equipped with rear swing squeegees which pivot about a vertical axis during turns to project a longer effective blade length as compared to rigidly mounted squeegees. Longer effective blade lengths permit the blade to pass over more wetted surface, thereby retaining and recovering more of the cleaning solution. However, these rear squeegee designs have not entirely overcome the problems associated with recovering cleaning solution during turns, because conventional rear squeegees do not pass over the entire wetted surface, even when they are arcuate and pivot.
Some prior scrubbers have rigidly mounted side squeegees which extend parallel with the sides of the scrubber frame and retain most of the cleaning solution beneath the machine during turns. However, because the motion of the machine during turns is not exactly perpendicular to the side squeegees, some of the cleaning solution flows parallel to the side squeegees and eventually flows past the ends of the squeegees so that streaks of cleaning solution trail behind the machines. The cleaning solution usually flows past the front end of the inside side squeegee during turns due to the angle and location of the inside side squeegee relative to the center of turning.
In order to prevent the cleaning solution from flowing parallel to the side squeegees and past their forward ends, some scrubbers have been manufactured so that the side squeegees pivot during turns to an orientation where the fluid is directed rearward toward the rear squeegee. The pivoting side squeegees are connected to the rear squeegees by linkages which drive the side squeegees between a straight-traveling position in which they are generally parallel with the side of the scrubber, and the turning positions in which the inside squeegee angles forward and inward, and the outside squeegee angles forward and outward. However, these linkages increase the complexity of the solution recovery system thereby increasing the cost and risk of failure.